Automatic proportioner

ABSTRACT

An actuator and control circuit for a standard syringe having calibration rods, including a first stop selectively engageable with one calibration rod and a second stop engageable with the other calibration rod so that the former stop can be moved out of the way of an abutment carried by the actuator permitting the actuator to drive the syringe and the abutment to the second stop, there also being provided a valve for selectively communicating the syringe with either a reagent conduit or a sample conduit with a control circuit for the actuator, valve and the movable stop which moves the movable stop into engagement with its associated calibration rod and drives the abutment toward the movable stop while the valve connects the syringe to the reagent conduit, and thereafter under manual control releases the movable stop, shifts the valve to a position connecting the syringe to the sample conduit and drives the actuator and abutment to the second stop, and thereafter in response to a manually operable delivery control retracts the actuator and maintains the valve in a position connecting the sample conduit to the syringe thereby discharging both the sample and the reagent through the sample conduit.

United States Patent Inventors Orin Lew Wood Murray; Gale l-I. Thorne;William P. Davis, Salt Lake City, Utah AUTOMATIC PROPORTIONER 17 Claims,12 Drawing Figs.

US. Cl 222/134, 222/136, 2221334 Int. Cl B67d 5/56 Field of Search222/43, 134, 136, 137, 145, 309, 334

References Cited UNITED STATES PATENTS 2,774,364 12/1956 Brobeil..222/136X 3,401,839 9/1968 Christie 222/137 Primary ExaminerRobert B.Reeves Assistant Examiner-H. S. Lane Attorney-Lynn G. Foster ABSTRACT:An actuator and control circuit for a standard syringe havingcalibration rods, including a first stop selectively engageable with onecalibration rod and a second stop engageable with the other calibrationrod so that the former stop can be moved'out of the way of an abutmentcarried by the actuator permitting the actuator to drive the syringe andthe abutment to the second stop, there also being provided a valve forselectively communicating the syringe with either a reagent conduit or asample conduit with a control circuit for the actuator, valve and themovable stop which moves the movable stop into engagement with itsassociated calibration rod and drives the abutment toward the movablestop while the valve connects the syringe to the reagent conduit, andthereafter under manual control releases the movable stop, shifts thevalve to a position connecting the syringe to the sample conduit anddrives the actuator and abutment to the second stop, and thereafter inresponse to a manually operable delivery control retracts the actuatorand maintains the valve in a position connecting the sample conduit tothe syringe thereby discharging both the sample and the reagent throughthe sample conduit.

22 f 23 I I V; 1 I w f l l La \\j My 130 151 l PATENTEU JAN28 IBYI SHEET3 OF 5 PATENTED JANZS I97! sum u 0F 5 ZA W w 5% if AUTOMATICPROPORTIONER BACKGROUND OF THE PRESENT INVENTION There have beenprovided in the past various devices for proportioning two fluids, andmore particularly, for proportioning two liquids. Such devices aregenerally of utility in chemical analysis of one of the fluids and insuch analysis it is desirable to dilute the fluid under analysis with adiluent for the purpose of subsequent analysis. An exemplary analysiswhere devices of this character find utility are in hemoglobinmeasurement.

A syringe type proportioning device known in the art for this generalpurpose includes a plunger with a telescopic barrel member slidablyreceived on the plunger and defining a syringe. Such a construction isshown and described in detail in the Marbach et al. US Pat. No.3,326,423 and reference should be made thereto for a more completedescription of the proportioner device. Generally, this device includestwo calibration rods extending axially upwardly from the base of theplunger along the side of the barrel itself. The difference in length ofthese two calibration rods determines the volume of the sample to bedrawn by the proportioning device. A flange is provided on the bottom ofthe slidable barrel member for selective engagement with the ends of therods during operation of the device.

This device has been operated manually in the following manner. Aftersuitable washing the pipet connected to the end of the barrel member isemersed in a suitable diluent or reagent and the barrel member is slidoutwardly from the plunger drawing diluent into the pipet and the barrelmember until the flange on the bottom of the barrel member reaches theposition where it can be rotated onto the top of the shorter calibrationrod, and at this point, the operator must push downwardly on the barrelmember to assure an accurate amount of diluent. After wiping the excessdiluent from the end of the pipet while maintaining the flange in tightengagement with the shorter calibration rod the operator then emersesthe pipet in the sample and rotates the flange into engagement with thelonger calibration rod and further extends the barrel from the plungerdrawing the sample into the pipet This is generally a very shortmovement as the sample required for most analyses is very small incomparison to the diluent, e.g., not over percent. As the flange reachesthe end of the longer calibration rod, which may be beveled, theoperator rotates the flange carefully on top of the longer calibrationrod making certain that the barrel member has not been extended to aposition where the flange is beyond the longer calibration rod.

To discharge the sample and reagent, the operator places the pipet instill another container and rotates the flange clear of the calibrationrods and pushes the barrel member backdown to its retracted positionforcing both the sample and the diluent out of the proportioning device.

While this proportioning device has found considerable acceptance in thefield of chemical analysis, both because of its simplicity and itsextreme accuracy, it nevertheless requires a certain amount of manualdexterity to achieve accurate proportioning even though the deviceitself may be calibrated very accurately. Therefore, in accordance withthe present invention a proportioning device of this general characterhas been completely automated with a control system which permits thewithdrawal of the diluent, the withdrawal of the sample, and thedelivery of the sample and the diluent completely automatically underthe operation of pushbutton control. Certain features, as will appearhereinbelow, are applicable to proportioning devices even of a somewhatdifferent character than that described above.

SUMMARY OF THE PRESENT INVENTION In accordance with the presentinvention, an automatic actuator and control system is provided for asyringe proportioner of the type described generally above. It includesa double-acting reciprocating actuator for driving the barrel member inboth directions, as well as a selectively operable valve for connectingeither a sample pipet or a reagent tube to the barrel member. Thecalibration rods are utilized as locating elements for two stops forlimiting movement of the actuator. One of these stops which isengageable with the end of the longer calibration rod is immovable whilethe stop associated and engageable with the shorter calibration rod isselectively movable so that it may be withdrawn from the path of theactuator as it moves from the movable stop to the stationary stop duringa period when the sample is drawn into the sample pipet The controlcircuit is operable to drive the barrel and the actuator against themovable stop and at the same time connect the syringe with the reagentdrawing reagent into the syringe. The sample control circuit is arrangedso that when the sample button is depressed the movable stop will bewithdrawn and the barrel will be connected by the valve to the samplepipet so that the actuator drives the barrel member to the secondstationary stop drawing sample into the sample pipet.

A delivery control circuit associated with a delivery button is operablewhen actuated to reverse the actuator driving the barrel downwardly anddelivering both the sample and the diluent out the sample pipet intoanother container placed thereunder.

The control circuit is operable to automatically recycle when theactuator has driven the barrel member to its completely retractedposition and in response to such positioning of the actuator it reversesthe valve connecting the barrel member to the reagent conduit andreverses the actuator so the reagent is drawn into the syringe. At thesame time, a fluid signal is delivered to the movable stop to lower itinto engagement with the gauge rod so that the actuator stops at thelower stop and the proportioner is again ready to receive a sample.

A further feature of the present invention is that multiple samples maybe drawn into the the sample tip without contaminating the proportioneror tubing associated therewith. More particularly, a multiple samplecontrol circuit is provided which when the barrel member is in aposition where the actuator engages the uppermost stop after the samplehas been withdrawn switches the valve connecting the barrel member tothe reagent and activates the movable stop so that the movable stopdrives the actuator and barrel downwardly expelling diluent or reagent,but not sample, through the reagent conduit. The valve member at thistime serves to hold the sample in the sample tip since it is downstreamof the valve with respect to the barrel. When the movable stop engagesthe lower calibration rod the sample button may be depressed again andanother sample will be drawn into the sample pipet in the abovedescribed manner. Thereafter the double sample may be delivered bydepression of the delivery button in the above described manner.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a fragmentary section of anautomatic proportioner according to the present device;

FIG. 2 is a cross section taken generally along 2-2 of FIG. 1;

FIG. 3 is a fragmentary side elevation of the proportioner shown inFIGS. 1 and 2;

FIG. 4 is a section taken generally along line 4-4 of FIG. 3;

FIG. 5 is a section taken generally along line 55 of FIG. 4;

FIG. 6 is a schematic illustration ofthe syringe stop bracket and tang;

FIG. 7 is a schematic showing of the syringe stop bracket from the side;

FIG. 8 is a schematic illustration of the syringe stop bracket inengagement with the movable stop;

FIG. 9 is a schematic illustration of the stop bracket in engagementwith the stationary stop with the movable stop retracted;

FIG. is a cross section of a diaphragm operated valve used in the fluidhandling as well as the control circuit of the present invention;

FIG. 11 is a schematic illustration of the preferred control circuitaccording to the present invention; and

FIG. 12 is a somewhat modified control circuit according to the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.1-3, an automated proportioning device 10 is illustrated which is seento include generally housing members 11 and 12, a syringe assembly 13, asyringe stop bracket assembly 14, a syringe stop assembly 15, anactuator assembly 18 for driving the syringe stop bracket, and controlelements 20 mounted within housing 11 and controlled by sample anddelivery push buttons 22 and 23 as well as a multiple sample toggleswitch 24.

The syringe 13 is selectively connectable by a valve 25 to either asample pipet 26 through conduit 27 or a reagent conduit 28.

The syringe assembly 13 includes a base member 28' having a hollowplunger 29a extending upwardly therefrom. Slidable on the plunger 29a isa barrel member 31 having a suitable fitting 32 at the upper end thereofadapted to receive a main syringe conduit 33 shown schematically in FIG.1.

Fixed to the rear side of the syringe base 28' are calibration rods 29and 30. Calibration rods 29 and extend parallel to the barrel andplunger members and have upper locating surfaces 33' and 34 (see FIG. 8)which are spaced apart a precise distance to determine the desiredamount of movement of the barrel member 31 when the syringe is drawingsample into pipet 26 to accurately measure the sample.

The barrel member 31 has a flange 36 at its lower end. The syringe orproportioner 13 is of conventional construction and it should beunderstood that the automatic proportioner, ac tuator and control systemis adapted to receive different proportioners or syringes 13 havingcalibration rods 29 and 30 of different heights and calibrations.

The syringe 13 is mounted in the automatic proportioner 10 by locatingthe base on the upper surface ofa projecting boss 40 of the housing 12.The plunger 29a is held fixed in a stationary position and maintains thebase 28 in engagement with boss 40 by a clamp assembly 42 which includesa plate 43 fixed to projections 45 and 46 extending upwardly from theboss 40 fastened thereto by suitable fasteners 48. A recess 50 in theplate 43 has a central wedging surface 54 which is posi tioned betweenthe calibrating rods 29 and 30. A thumbscrew 56 has a camming endportion 58 which engages one side of the rod 29 and clamps this rod inposition. The other rod 30 is held in position in the recess 50 by anoverhanging plate 60 shown clearly in FIG. 2.

The stop bracket assembly 14 is provided for reciprocating the barrel 31and providing a stop for the barrel at predetermined calibrated pointsof movement to assure accurate proportioning. Toward this end, the stopbracket assembly is seen to include a generally flat U-shaped upperplate 62 partially surrounding the barrel member 31, a central stopplate 63 and a lower plate 64 fastened together as a unit by suitablefasteners 67 thereby clamping the stop bracket assembly to the flange36. Projecting from the stop plate 63 is a small stop tang 69 whichslides between the calibrated rods 29 and 30. As will appear below, thestop tang 69 cooperates to limit movement of the barrel member 31 to thedesired positions.

For reciprocating the stop bracket assembly 14 and the barrel 31, theactuator 18 includes a cylinder 71 with a piston 72 slidable thereinhaving a rod 74 projecting upwardly from the housing member 11, throughthe projecting boss 40 of the housing member 12 and is rigidly fixed toa slide member 77 slidably received on a stationary vertically extendingcarriage rod 78. Rod 78 is seated in boss 40. Suitable means may beprovided for supporting the other end of the carriage rod 78.

The carriage or slide 77 has arms 80 and 81 extending horizontally onthe upper surface thereof, flanking the proportioner barrel 31 andclosely received in recesses 84 between the lower stop plate 64 and theintermediate stop plate 63.

For the purpose of rotatively stabilizing the carriage 77 a projection86 extends rearwardly therefrom and has a recess 87 therein shownclearly in FIG. 2 which is slidable on a vertically extending stationaryrod 88 mounted in the housing boss 40.

Thus, as fluid is delivered to the double-acting actuator 18, the piston72 is operable through the carriage 77 to reciprocate the stop bracketassembly l4 and the syringe barre] 31 upwardly and downwardly on therelatively stationary plunger 29a.

The stop head assembly 15 is provided to effect accurate limit stops forthe stop bracket tang 69 after the diluent has been drawn into thesyringe as well as after the sample has been drawn into the sample pipet26. Toward this end, the stop head 15 is seen to include a block 90having a bore 91 extending vertically therethrough so that the block maybe selectively positioned on the main rod 78. The guide rod 88 isreceived in a suitable recess 93 in the block 90 to provide rotativealignment and stability to the block. For locking the block 90 to therod 78, a hand screw assembly 93 is provided.

Block 90 carries a stationary stop 94 having a lower surface 95engageable with the upper end 34 of the longer guide rod 30. The block90 is positioned after the proportioner or syringe has been fixed inposition by lowering the block 90 until the lower surface 95 of thestationary stop engages the end of the longer rod and at that time thehandscrew 93 is tightened securely locking the stop head assembly 15inposition.

The stop surface 95 limits the end of the sample stroke of the barrel 3]by engagement with the tang 69 as it moves upwardly with the stopbracket assembly 14.

For limiting movement of the stop bracket assembly 14 in its upwardmovement when drawing diluent into the syringe 13 a movable stop 97 isprovided with a lower surface 98 selectively engageable with the uppersurface 33' of the shorter calibrated rod 29.

As seen more clearly in FIG. 5, the stop 97 is carried by a stop pin 99slidable in a vertical bore 100 in the block 90. The pin 99 is shown inFIG. 5 in its uppermost position and has a central reduced stem portion101 which cooperates with a threaded member 104 projecting within bore100 to prevent the pin 99 and the stop 97 from falling out of the bore.

A diaphragm operator 105 is provided for driving the pin 99 and the stop97 downwardly until stop surface 98 engages the upper surface of theshorter calibration rod. The diaphragm operator is seen to include ahousing 106 fixed to the stophead 90 by suitable fasteners (not shown)and having an annular chamber 108 with a diaphragm 110 therein having arigid member 111 fixed thereto. Diaphragm 110 separates the chamber 108into chamber 108a and 108b. For supplying fluid to the chamber 108a asuitable air fitting 112 is provided and when fluid is supplied tochamber 108a the diaphragm shifts to the right against the bias of thespring 114 forcing a pin 115 slidable in block 90 to the right. Pin 115and pin 99 have interengaging conical surfaces 118 and 119 respectively.As the pin 115 moves to the right from its inactive position shown inFIG. 5, conical surface 118 engages conical surface 119 and drives thepin 99 and stop 97 downwardly. When the delivery of fluid under pressureto fitting 112 is terminated spring 114 returns the diaphragm and pin115 to its right position shown in FIG. 5.

Referring more particularly to FIG. 1, the control circuitry 20 ismounted within the frame member 11 and includes generally a manifoldboard carrying pushbutton valves 126 and 127 associated with the sampleand delivery buttons 22 and 23 respectively. Also mounted on themanifold board are valves 130 and 131' as well as as a fluid amplifier133. The various air fittings are defined by barbed members such as at134 extending or projecting from the manifold member 125 thus providinga unitized control circuit for the proportioner.

Referring to FIGS. 6-9 for description of gauging of the present device,let it be assumed that the barrel 31 is in its lowermost position and isdriven upwardly by the actuator 18 with stop bracket plate 63 and stoptang 69 at a time when the valve 25 connects the reagent tube to themain syringe conduit 33. This draws reagent or diluent into the syringe.The control circuit described in more detail below supplies air pressureto the diaphragm operator 105 forcing the stop pin 99 downwardly untilthe lower surface 98 of the movable stop engages the top of the shorterrod 29. Movement of the barrel 31 continues upwardly until tang 69engages stop 97 as shown clearly in FIG. 8. The control circuit thenreleases the fluid pressure applied to the diaphragm operator 105 and atthe same time switches valve 25 to connect the main syringe conduit 33to sample conduit 27. The actuator then automatically drives the tang 69and the barrel 3] upwardly and the tang in turn drives the movable stop99 upwardly until the tang engages the stationary stop 94 as shown inFIG. 3. This latter movement of the syringe barrel 31 serves toaccurately draw the sample fluid into the sample pipet 26.

It should be understood from the above description that the present stopassembly may be used with a plurality of proportioners of different sizeand calibration since the fixed stop 94 may be positioned by positioningblock 90 and the movable stop 97 can accommodate a wide range of shortcalibration rods 29.

A liquid handling valve 25 is shown in more detail in FIG. and while thedetails thereof form no part of the present invention, certain functionsof the valve are particularly useful in the operation of the presentautomatic proportioner. This valve is shown and described in more detailin the application of William P. Davis, Ser. No. 794,099, filed Jan. 27,1969, assigned to the assignee of the present invention, and referenceshould be made thereto for a more complete understanding thereof.Briefly, however, the valve 25 consists of a valve block 130 having arecess 131 therein slidably receiving and guiding a movable valve slide136 for rectilinear movement from a position connecting main conduit 33with reagent conduit 28 as shown in the drawing to a right-hand positionconnecting main conduit 33 with sample conduit 27. It should beunderstood that one of the functions of the valve slide 136 is to sealthe conduit 27 when conduit 33 is connected to conduit 28 so that anysample in conduit 27 will be held therein by the sealing engagement ofvalve slide 136 with valve block recess 131. Diaphragm operatingassemblies 138 and 139 are provided for shifting the valve slide 136from its reagent coupling position shown in FIG. 10 to its right-handsample coupling FIG. and back to the position shown. Diaphragm operator138 includes an air fitting 140 and diaphragm operator 139 includes anair fitting 141, both adapted to be selectively connected to sources ofair supply from the control circuit described in more detail below.

The control circuit shown in FIG. 11 is adapted to automatically cyclethe proportioner to the position shown where the stop 97 is in itsactuated position and the barrel member 31 is moved upwardly to aposition where tang 69 engages stop.97. Thus, at the beginning and atthe end of each cycle the reagent has already been drawn into thesyringe 13. Moreover, the control circuit is operable to connect thesyringe conduit 33 to the reagent conduit 28.

Beginning at this point in the operation, if the operator desires asingle sample offluid to be drawn into the sample tip, he inserts thesample tip into a sample receptacle and depresses the sample button 22actuating the pushbutton valve 126. The sample valve as well as theother valves in the system are connected to asuitable source of supplyindicated schematically at 145 through a suitable regulator 146 and afluid supply line 147.

The depression of sample button 22 ports fluid through line 150 to oneside of valve 130' shifting the valve to connect supply line 147 withpassageway 148 supplying fluid to the diaphragm operator 138 causingvalve 25 to connect main syringe conduit 33 to sample conduit 27. Valve130' may preferably take the same form as the valve 25 described in moredetail above. The shifting of valve 130' depressurizes outlet line 150and stop control line 151 thereby depressurizing the diaphragm operatorfor stop 97. This permits the barrel member 31 along with the stop tang69 to be driven upwardly by the actuator 18 drawing sample fluid intothe sample tip 26, until tang 69 engages stop 94.

The accurately proportioned sample and diluent or reagent are thendischarged from the sample tip by the operator after placing the tip ina suitable container, by the depression of delivery button 23. Thisports supply fluid through pushbutton valve 127, through passage 152 tothe lower side of valve 131' shifting the valve to the position shown inthe drawing connecting supply conduit 154 to actuator feed line 156.Valve 131' is similar in construction to valve 25 and serves toselectively deliver fluid to the opposite sides of piston 72. The piston72 is thus driven downwardly along with the barrel 31 discharging thesample and the reagent through the sample tip 26 until completelydischarged when barrel 31 reaches its lowermost position.

The actuator and the barrel member automatically move back to theposition shown in FIG. 11 in response to the actuator and barrel memberreaching their lowermost positions. Toward this end, and with the togglevalve 24 in its position shown connecting conduit 158 with conduit 160and conduit 161, the discharge of fluid through the toggle valve andconduit 161 as the piston 72 reaches its lowermost position, actuates apin and diaphragm type amplifying valve 133 constructed to provide asufficient signal in line 167 when the piston 72 reaches its lowermostposition. The fluid signal in line 167 is delivered to the upper side ofvalve shifting it downwardly to a position connecting line 147 and lineThis resets the stop 97 to its lowermost position and shifts valve 25upwardly to a position connecting syringe conduit 33 and reagent conduit28. At the same time, the pressure in line 168 shifts valve 131'downwardly connecting supply conduit 154 and delivery conduit drivingthe actuator 18 upwardly while the syringe is connected to the reagentconduit drawing reagent into the syringe until the stop tang 69 engagesthe bottom ofstop 97, at which time the apparatus is at rest.

There is also provided according to the present invention, means fordelivering multiple samples for a given amount of diluent withoutcontaminating the main syringe line 33 with any portion of the samplefluid. It should be noted that the samples are generally of such a smallvolume that they remain in the sample pipet 26 and are never drawn intothe main conduit 33.

Assuming that a'multiple, or at least one additional sample is requiredand the sample button 22 has already been depressed so that the barrel31 is in its uppermost position with tang 69 engaging the upper stop 94,the operator switches the multiple sample toggle to its right positionconnecting line 158 with line 175. This connects the lower part ofactuator 18 from the pressure source 154 and pressurizes line 175, andline 178 shifting valve 130' downwardly, connecting supply passage 147and 150 thereby shifting the valve 25 to connect syringe conduit 33 toreagent conduit 28 and at the same time pressurizing the movable stopdiaphragm operator 105 driving the stop 97 downwardly along with tang 69until the stop 97 abuts the shorter calibration rod 29. Since thepressure in the lower half of the actuator has been relieved and thepressure applied to the diaphragm operator 105, this downward movementof the barrel is permitted. The operator then moves the toggle valve 24back to the normal position shown, and then the system is ready toreceive another sample. The operator may then depress sample button 22and a second sample will be drawn into the sample tip 26. Thereafterboth samples along with a single quantity or volume of diluent may bedelivered to the sample tip by the depression of the delivery button 23.

A somewhat modified form of the present invention is shown in FIG. 12.The proportioner 13, the stop pin 97, the actuator 18, the deliverybutton 23 and associated valve 127,

the sample button 22 and associated valve 126 are identical to thatdescribed above. The difference in the circuit shown in FIG. 12 is thatit employs pure fluidic elements rather than movable part valve membersin several instances and does not include either the automatic recyclingfeature of the circuit of FIG. 11 or the multiple sample capability.

The fluidic elements 180 and 181 are provided as the primary controlcomponents of this circuit. These fluidic elements are of well-knownconstruction in the pure fluidic art and are referred to generally asfluidic flip-flops in that they are bistable devices. Both are connectedto a source of supply 185a and 18511 and shift supply fluid from oneoutlet port to another in response to the application of one of twoopposed fluid signals interacting with the supply stream. The bistablecharacteristic of this device is achieved by conventional wallattachment techniques, which is well known in the fluidic art.

Assuming the barrel 3] to be in its lowermost position along withactuator 18, the operator presses the reagent button 188 supplying fluidto upper signal port 190 associated with valve 180 shifting the outletflow to outlet passage 192 supplying fluid to the underside of piston 72driving the piston upwardly. At the same time, a fluid signal isprovided in line 193 shifting the fluidic element 181i to supply fluidthrough line 196 which actuates a pinch valve 198 occluding the sampleconduit 27 and at the same time depressurizing line 199 releasing pinchvalve 201 and providing communication between reagent line 28 andsyringe conduit 33. At the same time, line 204 is pressurizcd actuatingthe stop pin 97 to its lowermost position. The actuator then movesupwardly drawing reagent into the syringe until the stop tang engagesthe movable stop 97.

The operator then may draw sample into the device by pressing samplebutton 22 providing a signal in line 206 which switches flip-flop 181 toconnect line 191 with supply and depressurize line 196 so that pinchvalve 201 occludes line 198 and pinch valve 198 is released, and at thesame time line 204 is depressurized releasing the stop 97. Sinceflip-flop 180 is already pressurizing line 192 the actuator 18automatically drives the barrel 31 upwardly into engagement with theupper stop drawing sample into sample line 27.

To deliver the sample, the delivery button 23 is depressed providing asignal in line 210 switching flip-flop 180 to pressurize line 212 anddepressurize line 192 driving the actuator and the barrel 31 downwardlydelivering both sample and diluent out sample line 27.

We claim:

1. An automatic driver and controller for a fluid proportioning deviceof the type having a plunger member and a relatively movable telescopicbarrel member, comprising: first conduit means adapted to be connectedto convey fluid to and from said barrel member, second conduit meansadapted to communicate with a first fluid, third conduit means adaptedto be connected to a sample fluid, valve means for selectivelyconnecting one of said second and third conduit means to said firstconduit means, actuator means for moving one of said members andselectively drawing fluid through said second and sample conduits,control means for said actuator means to limit movement of said movablemember when said valve means communicates said first and sample conduitmeans to a predetermined sufficiently small value so that the samplefluid does not enter the first conduit but remains in the sample conduitmeans.

2. An automatic driver and controller as defined in claim 1, includingmeans for delivering multiple samples including second control meansmoving said valve means to a position connecting said first and secondconduit means and simultaneously moving said actuator in a direction toexpel at least a portion of said first fluid from said first conduit tosaid second conduit, said valve means at that time being constructed tohold the predetermined sample in said sample conduit means, said controlmeans thereafter being operable to move said movable member in adirection drawing said second fluid from said third sample conduit meanstoward said first conduit means, said actuator means then being movablein the opposite direction after the control means connects said firstconduit means to said sample conduit means whereby a secondpredetermined sample may be drawn through said sample conduit means.

3. An automatic driver and controller as defined in claim 2. includingfirst stop means for limiting movement ofsaid movable member while saidfirst fluid is being drawn through said first conduit means, second stopmeans for limiting movement of said movable member after a predeterminedamount of sample fluid is drawn through said sample conduit means, saidcontrol means including means for moving said movable member to saidfirst stop means, and at the same time moving the valve means to connectsaid first and second conduit means, third control means controllingsaid first and second control means to move said valve means to aposition connecting said first and sample conduit means and to move saidmovable member to said second stop, said means for deliver ing multiplesamples including fourth control means for controlling said first andsecond control means to move the valve means to a position connectingsaid first and second conduit means and to move said movable member in adirection expelling fluid from said second conduit means therebypermitting the movable member to return to the first stop ready to drawa second sample.

4. A control system for a proportioner of the type having a plungermember and a telescopic barrel member movable relative thereto toproportion accurate volumes of two or more fluids, comprising: firststop means for accurately limiting movement of the movable one of saidmembers during drawing of a first fluid, second stop means for limitingmovement of said movable member during drawing of a second fluid, fluidoperable actuator means for moving said movable member from apredetermined retracted position to said first stop means, from saidfirst stop means to said second stop means, and from said second stopmeans back to said retracted position, first conduit means adapted tocommunicate with one of said members, second conduit means adapted tocommunicate with a first fluid, third conduit means adapted to beconnected to a sample fluid, valve means for selectively connecting saidfirst conduit means to one of said second or third conduit means,manually operable sample control means for moving said movable memberfrom said first stop means to said second stop means and for moving saidvalve means to a position connecting said first and third conduit means,and manually operable delivery control means for moving said movablemember from said second stop means to said retracted position and formoving said valve means to a position connecting said first conduitmeans and said third conduit means.

5. A control system for a proportioner as defined in claim 4, includingsecond valve means for selectively porting fluid to said actuator todrive said actuator in a first direction from said retracted position ora second direction toward said retracted position, fluid operable meansfor moving said first valve means, and control means for automaticallycontrolling said fluid operable means to move the valve means to aposition connecting said first and second conduit means and controllingsaid second valve means to move the actuator means in said firstdirection toward said first stop means, andautomatic control means beingresponsive to actuator movement to a retracted position corresponding tothe retracted position of the movable member whereby the cycle of theproportioner ends and begins at the first stop means.

6 An automatic proportioner for two fluids, comprising: a syringeincluding a stationary plunger member and a movable member cooperatingwith said stationary plunger member to vacuum draw fluid toward saidstationary plunger member, first locating means fixed with respect tosaid stationary plunger member and representing by position the desiredamount of one of said fluids, second locating means separate from thefirst locating means and fixed with respect to said sta tionary plungermember and representing by'its distance from the first locating meansthe desired amount of the other fluid,

first stop means separate from but adapted to contact said firstlocating means, second stop means separate from but adapted to contactsaid second locating means, and actuator means for moving said movablemember to predetermined position with respect to said first stop meansdrawing by vacuum pressure one of said fluids toward said stationaryplunger member during said first movement and for thereafter moving saidmovable member to a predetermined position with respect to said secondstop means for drawing by vacuum pressure the other of said fluidstoward said stationary plunger member.

7. An automatic proportioner for two fluids, comprising: a syringeincluding a stationary plunger member and a movable member cooperatingwith said stationary plunger member to draw fluid toward said stationaryplunger member, first locating means fixed. with respect to saidstationary plunger member and representing by position the desiredamount of one of said fluids, second locating means fixed with respectto said stationary plunger member and representing by its distance fromthe first locating means the desired amount of the other fluid, firststop means selectively movable into and out of engagement with saidfirst locating means, second stop means engageable with said secondlocating means, abutment means on said movable member adapted toserially engage the first and second stop means only at predeterminedtimes during a cycle of the proportioner, actuator means for moving saidmovable member to a position where the abutment means engages said firststop means, control means for thereafter releasing said first stop meanssaid actuator means moving said movable member to another position wheresaid abutment means engages said second stop means.

8. An automatic proportioner as defined in claim 7 wherein said actuatormeans includes control means for biasing said abutment means againstsaid first stop means so that when the first stop means is released bysaid first control means the actuator means will automatically move to aposition where the abutment means is in engagement with said second stopmeans.

9. An automatic proportioner as defined in claim 8 wherein said actuatormeans includes a double-acting piston and cylinder device, said secondcontrol means including means for delivering fluid to said actuatormeans to drive the moveable member in a first direction drawing fluidinto said plunger member, said second control means maintaining thefluid pressure on the appropriate side of said piston to continue urgingsaid movable member in said first direction after said abutment meansengages said first stopmeans so that when the first stop means is movedthe piston will automatically drive the movable member to a positionwhere the abutment means engages the second stop without further controlby said second control means.

10. A device for automatically controlling a fluid proportioner of thetype having a stationary plunger member and a relatively movabletelescopic barrel member with at least two calibration means fixed withrespect to one of said members, comprising: first stop means selectivelymovable into physical contact with said first calibrating means, secondstop means physically engageable with said second calibrating means,abutment means on said movable member and normally spaced from the firstand second stop means, actuator means for moving said movable member toa position where the abutment means contacts said first stop means, tomomentarily restrain further movement of the movable member, controlmeans for thereafter moving said first stop means, said actuator movingsaid movable member to a position where said abutment means contactssaid second stop means to terminate said last-mentioned movement of themovable member.

11. A device as defined in claim 10, including an elongated support forone of said members, stop head means on said elongated support havingsaid second stop means fixed thereon, said stop head means beingpositionable along said support to a place where the second stop meansengages said second calibrating means, means for fixing said stop headmeans on said support in said place, said first stop means being carriedby said stop head means and being movable from a retracted position to aplurality of extended positions whereby the device can accommodateproportioners having differently positioned calibration means.

12. A device as defined in claim 11, including fluid operable means forshifting said first stop means from its retracted position intoengagement with said first calibration means, said fluid operable meansbeing carried by said stop head means.

13. A device as defined in claim 12, wherein said control means formoving said stop means is independent of actuator movement.

14. A device as defined in claim 10 including an elongated movablesupport for one of said members, slide means on said elongated movablesupport engageable with and fixed with respect to the movable member,said abutment means being carried by said slide means.

15. A device as defined in claim 10, including first conduit meansadapted to be connected to said movable member to convey a first fluidthereto, second conduit means adapted to be connected to said movablemember to convey a second fluid thereto, valve means movable to a firstposition connecting said first conduit means to convey said first fluidto said movable member and block flow through said second conduit meansand a second position connecting said second conduit means to conveyfluid to said movable member and block flow through said first conduitmeans, said control means for moving said first stop means, said controlmeans for moving said first stop means also controlling said valve meansso that as said first stop means is retracted the valve means will movesubstantially simultaneously from said first position to said secondposition.

16. An automatic proportioner as defined in claim 15, including secondvalve means for controlling fluid flow to said actuator to move saidmovable member in a first direction drawing fluid toward said plungermember or a second direction expelling fluid from said movable memberthrough one of said conduit means, manually operable control means forcontrolling said control means to move said first valve means to saidsecond position to retract said first stop means to draw said firstfluid toward said plunger member through said second conduit means, andmanually operable delivery means for controlling said second valve meansto move said actuator means in said second direction, said deliverymeans not affecting said first valve means so that the fluid expelsthrough said one conduit means.

17. An automatic proportioner as defined in claim 16 wherein saidactuator means includes a double-acting piston and cylinder device,automatic means responsive to the completion of movement of saidactuator means in said second direction for activating said controlmeans to place said valve means in said first position and move saidfirst stop means in engagement with said first calibration means andalso to move the actuator in the first direction drawing fluid throughsaid first conduit means until said'abutment means engages with firststop means.

1. An automatic driver and controller for a fluid proportioning deviceof the type having a plunger member and a relatively movable telescopicbarrel member, comprising: first conduit means adapted to be connectedto convey fluid to and from said barrel member, second conduit meansadapted to communicate with a first fluid, third conduit means adaptedto be connected to a sample fluid, valve means for selectivelyconnecting one of said second and third conduit means to said firstconduit means, actuator means for moving one of said members andselectively drawing fluid through said second and sample conduits,control means for said actuator means to limit movement of said movablemember when said valve means communicates said first and sample conduitmeans to a predetermined sufficiently small value so that the samplefluid does not enter the first conduit but remains in the sample conduitmeans.
 2. An automatic driver and controller as defined in claim 1,including means for delivering multiple samples including second controlmeans moving said valve means to a position connecting said first andsecond conduit means and simultaneously moving said actuator in adirection to expel at least a portion of said first fluid from saidfirst conduit to said second conduit, said valve means at that timebeing constructed to hold the predetermined sample in said sampleconduit means, said control means thereafter being operable to move saidmovable member in a direction drawing said second fluid from said thirdsample conduit means toward said first conduit means, said actuatormeans then being movable in the opposite direction after the controlmeans connects said first conduit means to said sample conduit meanswhereby a second predetermined sample may be drawn through said sampleconduit means.
 3. An automatic driver and controller as defined in claim2, including first stop means for limiting movement of said movablemember while said first fluid is being drawn through said first conduitmeans, second stop means for limiting movement of said movable memberafter a predetermined amount of sample fluid is drawn through saidsample conduit means, said control means including means for moving saidmovable member to said first stop means, and at the same time moving thevalve means to connect said first and second conduit means, thirdcontrol means controlling said first and second control means to movesaid valve means to a position connecting said first and sample conduitmeans and to move said movable member to said second stop, said meansfor delivering multiple samples including fourth control means forcontrolling said first and second control means to move the valve meansto a position connecting said first and second conduit means and to movesaid movable member in a direction expelling fluid from said secondconduit means thereby permitting the movable member to return to thefirst stop ready to draw a second sample.
 4. A control system for aproportioner of the type having a plunger member and a telescopic barrelmember movable relative thereto to proportion accurate volumes of two ormore fluids, comprising: first stop means for accurately limitingmovement of the movable one of said members during drawing of a firstfluid, second stop means for limiting movement of said movable memberduring drawing of a second fluid, fluid operable actuator means formoving said movable member from a predetermined retracted position tosaid first stop means, from said first stop means to said second stopmeans, and from said second stop means back to said retracted position,first conduit means adapted to communicate with one of said members,second conduit means adapted to communicate with a first fluid, thirdconduit means adapted to be connected to a sample fluid, valve means forselectively connecting said first conduit means to one of said second orthird conduit means, manually operable sample control means for movingsaid movable member from said first stop means to said second stop meansand for moving said valve means to a position connecting said first andthird conduit means, and manually operable delivery control means formoving said movable member from said second stop means to said retractedposition and for moving said valve means to a position connecting saidfirst conduit means and said third conduit means.
 5. A control systemfor a proportioner as defined in claim 4, including second valve meansfor selectively porting fluid to said actuator to drive said actuator ina first direction from said retracted position or a second directiontoward said retracted position, fluid operable means for moving saidfirst valve means, and control means for automatically controlling saidfluid operable means to move the valve means to a position connectingsaid first and second conduit means and controlling said second valvemeans to move the actuator means in said first direction toward saidfirst stop means, and automatic control means being responsive toactuator movement to a retracted position corresponding to the retractedposition of the movable member whereby the cycle of the proportionerends and begins at the first stop means. 6 An automatic proportioner fortwo fluids, comprising: a syringe including a stationary plunger memberand a movable member cooperating with said stationary plunger member tovacuum draw fluid toward said stationary plunger member, first locatingmeans fixed with respect to said stationary plunger member andrepresenting by position the desired amount of one of said fluids,second locating means separate from the first locating means and fixedwith respect to said stationary plunger member and representing by itsdistance from the first locating means the desired amount of the otherfluid, first stop means separate from but adapted to contact said firstlocating means, second stop means separate from but adapted to contactsaid second locating means, and actuator means for moving said movablemember to predetermined position with respect to said first stop meansdrawing by vacuum pressure one of said fluids toward said stationaryplunger member during said first movement and for thereafter moving saidmovable member to a predetermined position with respect to said secondstop means for drawing by vacuum pressure the other of said fluidstoward said stationary plunger member.
 7. An automatic proportioner fortwo fluids, comprising: a syringe including a stationary plunger memberand a movable member cooperating with said stationary plunger member todraw fluid toward said stationary plunger member, first locating meansfixed with respect to said stationary plunger member and representing byposition the desired amount of one of said fluids, second locating meansfixed with respect to said stationary plunger membeR and representing byits distance from the first locating means the desired amount of theother fluid, first stop means selectively movable into and out ofengagement with said first locating means, second stop means engageablewith said second locating means, abutment means on said movable memberadapted to serially engage the first and second stop means only atpredetermined times during a cycle of the proportioner, actuator meansfor moving said movable member to a position where the abutment meansengages said first stop means, control means for thereafter releasingsaid first stop means said actuator means moving said movable member toanother position where said abutment means engages said second stopmeans.
 8. An automatic proportioner as defined in claim 7 wherein saidactuator means includes control means for biasing said abutment meansagainst said first stop means so that when the first stop means isreleased by said first control means the actuator means willautomatically move to a position where the abutment means is inengagement with said second stop means.
 9. An automatic proportioner asdefined in claim 8 wherein said actuator means includes a double-actingpiston and cylinder device, said second control means including meansfor delivering fluid to said actuator means to drive the moveable memberin a first direction drawing fluid into said plunger member, said secondcontrol means maintaining the fluid pressure on the appropriate side ofsaid piston to continue urging said movable member in said firstdirection after said abutment means engages said first stop means sothat when the first stop means is moved the piston will automaticallydrive the movable member to a position where the abutment means engagesthe second stop without further control by said second control means.10. A device for automatically controlling a fluid proportioner of thetype having a stationary plunger member and a relatively movabletelescopic barrel member with at least two calibration means fixed withrespect to one of said members, comprising: first stop means selectivelymovable into physical contact with said first calibrating means, secondstop means physically engageable with said second calibrating means,abutment means on said movable member and normally spaced from the firstand second stop means, actuator means for moving said movable member toa position where the abutment means contacts said first stop means, tomomentarily restrain further movement of the movable member, controlmeans for thereafter moving said first stop means, said actuator movingsaid movable member to a position where said abutment means contactssaid second stop means to terminate said last-mentioned movement of themovable member.
 11. A device as defined in claim 10, including anelongated support for one of said members, stop head means on saidelongated support having said second stop means fixed thereon, said stophead means being positionable along said support to a place where thesecond stop means engages said second calibrating means, means forfixing said stop head means on said support in said place, said firststop means being carried by said stop head means and being movable froma retracted position to a plurality of extended positions whereby thedevice can accommodate proportioners having differently positionedcalibration means.
 12. A device as defined in claim 11, including fluidoperable means for shifting said first stop means from its retractedposition into engagement with said first calibration means, said fluidoperable means being carried by said stop head means.
 13. A device asdefined in claim 12, wherein said control means for moving said stopmeans is independent of actuator movement.
 14. A device as defined inclaim 10 including an elongated movable support for one of said members,slide means on said elongated movable support engageable with and fixedwith respect to the movable member, said abutment means being carried bysaid slide means.
 15. A device as defined in claim 10, including firstconduit means adapted to be connected to said movable member to convey afirst fluid thereto, second conduit means adapted to be connected tosaid movable member to convey a second fluid thereto, valve meansmovable to a first position connecting said first conduit means toconvey said first fluid to said movable member and block flow throughsaid second conduit means and a second position connecting said secondconduit means to convey fluid to said movable member and block flowthrough said first conduit means, said control means for moving saidfirst stop means, said control means for moving said first stop meansalso controlling said valve means so that as said first stop means isretracted the valve means will move substantially simultaneously fromsaid first position to said second position.
 16. An automaticproportioner as defined in claim 15, including second valve means forcontrolling fluid flow to said actuator to move said movable member in afirst direction drawing fluid toward said plunger member or a seconddirection expelling fluid from said movable member through one of saidconduit means, manually operable control means for controlling saidcontrol means to move said first valve means to said second position toretract said first stop means to draw said first fluid toward saidplunger member through said second conduit means, and manually operabledelivery means for controlling said second valve means to move saidactuator means in said second direction, said delivery means notaffecting said first valve means so that the fluid expels through saidone conduit means.
 17. An automatic proportioner as defined in claim 16wherein said actuator means includes a double-acting piston and cylinderdevice, automatic means responsive to the completion of movement of saidactuator means in said second direction for activating said controlmeans to place said valve means in said first position and move saidfirst stop means in engagement with said first calibration means andalso to move the actuator in the first direction drawing fluid throughsaid first conduit means until said abutment means engages with firststop means.